Method and apparatus for treating a workpiece with arrays of nozzles

ABSTRACT

The present invention provides a tool for treating microelectronic workpieces with one or more treatment materials, including liquids, gases, fluidized solids, dispersions, combinations of these, and the like.

PRIORITY CLAIM

This application is a divisional of U.S. patent application Ser. No.13/649,742, filed Oct. 11, 2012, which is a divisional of U.S. patentapplication Ser. No. 11/820,709, filed Jun. 20, 2007,wherein therespective entirety of each of said nonprovisional applications isincorporated herein by reference and wherein U.S. patent applicationSer. No. 11/820,709 claims priority under 35 USC §119(e) from U.S.Provisional Patent Application having Ser. No. 60/819,133, filed on Jul.7, 2006, wherein the respective entirety of said provisional patentapplication is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to barrier plates and dispense assembliesfor tools used to process microelectronic substrates with one or moretreatment fluids, including liquids and gases. More particularly, thepresent invention relates to such tools that include barrier plates anddispense assemblies with improved fluid flow, fluid containment, thermalaccommodation, and/or drying capabilities.

BACKGROUND OF THE INVENTION

The microelectronic industry relies on a variety of different processesto manufacture microelectronic devices. Many processes involve asequence of treatments in which different kinds of treatment fluids arecaused to contact the workpiece in accordance with desired recipes.These fluids may be liquids, gases, or combinations thereof. In sometreatments, solids may be suspended or dissolved in a liquid orentrained in a gas. It is highly desirable to capture and recover thesetreatment fluids for a variety of reasons including proper disposal,recycling, fume containment, process monitoring, process control, orother handling.

One capture technique involves using appropriately positioned ducts tocapture treatment fluids. For instance, a typical manufacturing tool inthe microelectronics industry involves supporting one or more workpiecesin a processing chamber on a suitable support, such as a stationaryplaten, rotating turntable, or rotatable chuck. One or more ducts arepositioned at least partially around the outer periphery of the support.As a treatment fluid is introduced into the processing chamber, anexhaust can be used to help pull the treatment fluid into the one ormore ducts. With respect to rotating supports, centrifugal force causesfluids on a spinning workpiece and/or support surface to flow radiallyoutward from the spin axis and into the duct(s).

Conventionally, a tool may include a single duct to capture differenttreatment fluids. However, using a single duct like this is notdesirable in all instances. For example, some treatment fluids may betoo reactive in the presence of other treatment materials. Other times,it may be desirable to capture different fluids using different captureconditions. Still other times, such as when recycling is desired, it maybe desirable to capture a fluid in a dedicated duct to avoidcontamination with other fluids.

Accordingly, tools containing multiple, stacked ducts, fixed relative toeach other, have been used. Either the workpiece support and/or thestacked ducts themselves are raised and lowered in order to bring theappropriate duct into position. This conventional approach suffers fromserious drawbacks. The stacked ducts make high-density tool packagingmore difficult. The different ducts may also be subject tocross-contamination because they are always open to the workpiece and/orexhaust levels are not individually controlled. Some conventional ductsystems also may not have the capability to separate the liquid and gasconstituents of an exhaust stream. In some tools in which the ductstructures themselves are moveable, drain and exhaust connections toexternal plumbing must also move, thereby adding undue complexity totool design, manufacture, use, and service.

An innovative tool incorporating a flexible duct system is described inAssignee's co-pending U.S. Patent Publication No. US-2007/0022948-A1(hereinafter referred to as the Co-Pending Application No. 1); as wellas in Assignee's co-pending U.S. patent application Ser. No. 11/376,996,titled BARRIER STRUCTURE AND NOZZLE DEVICE FOR USE IN TOOLS USED TOPROCESS MICROELECTRONIC WORKPIECES WITH ONE OR MORE TREATMENT FLUIDS, inthe names of Collins et al., filed Mar. 15, 2006, and bearing AttorneyDocket No. FSI0166US (hereinafter referred to as the Co-PendingApplication No. 2). The entireties of these co-pending U.S. PatentApplications are incorporated herein by reference for all purposes. The“processing section 11” of the co-pending U.S. Patent Applicationsadvantageously includes nested duct features that allow one or more ductpathways to be selectively opened and closed. For example, when thestructures are moved apart relatively, a duct pathway opens and isenlarged between the structures. When the structures are moved togetherrelatively, the duct between the structures is choked and is reduced insize. In preferred embodiments, multiple ducts can exist in the samevolume of space depending upon how the moveable duct structures arepositioned. Thus, multiple ducts can occupy a volume minimally largerthan the volume occupied by only a single duct. The ducts are used tocapture various treatment fluids, including liquid and/or gases, forrecycling, discarding, or other handling. Different treatment fluids canbe recovered in different, independent ducts to minimizecross-contamination and/or to use unique capture protocols for differentfluids. Because of the nested character of the duct structures, the ductsystem also is extremely compact.

These co-pending U.S. Patent Applications also describe an innovativespray nozzle/barrier structure. This structure includes capabilities fordispensing treatment materials in multiple ways such as by a spray, acenter dispense, and a showerhead. The barrier structure overlies theunderlying workpiece. The lower surface of the barrier structure isshaped so that it defines a tapering flow channel over the workpiece.This approach offers many benefits. The tapering flow channel helps topromote radial flow outward from the center of the workpiece whileminimizing recirculation zones. The taper also helps to smoothlyconverge and increase the velocity of flowing fluids approaching theouter edge of the workpiece. This helps to reduce liquid splash effects.The angle of the lower surface also helps liquid on the lower surface todrain toward the outer periphery. The tapering configuration also helpsto reduce recirculation of particles back onto the workpiece. Theconfiguration also helps facilitate chemical reclaim efficiency bybetter containment of fluids.

Notwithstanding all these benefits, further improvements are stilldesired. Firstly, during the course of treating a workpiece, the lowersurface of the barrier structure may bear drops or films of liquid(s)used during the treatment. It would be desirable to find a way toeffectively clean and/or dry the lower surface of the barrier structurequickly without an undue impact upon cycle time.

As another issue, it has been observed that the central region ofworkpieces tends to be processed to a lesser degree when treated with aspray bar that spans generally only a radius of the underlyingworkpiece. Yet, using a radius-spanning spray bar rather than a fulldiameter spray bar is desirable for ease of manufacturing or when astream dispense is desired near the center of the workpiece. Thus, itwould be desirable to improve the processing uniformity of radial spraybars.

Also the previously known barrier structure incorporates a spray barmechanism as an integral member. The integrated component has arelatively large thermal mass. When heated materials are dispensedthrough the spray bar mechanism, the heat sink effect of the largethermal mass of the integrated components can cool the materials beingdispensed and affect the temperature uniformity of the materialscontacting the workpiece. This can impact the treatment performance inan undesirable way. Thus, there is a need to minimize this undesiredthermal impact.

Additionally, there is an issue concerning mist containment in theprocess chamber. The center area of the barrier structure is generallyopen, even during a treatment. The center area allows air flow andfunctions much like a chimney through which plumbing components and thelike are led to the dispensing components. During treatments,particularly spray treatments, some dispensed materials may have atendency to escape upward through the chimney. It would be verydesirable to contain the materials in the process chamber while stillleaving an air flow path open.

SUMMARY OF THE INVENTION

The present invention provides a tool for treating microelectronicworkpieces with one or more treatment materials, including liquids,gases, fluidized solids, dispersions, combinations of these, and thelike. The invention provides an approach for rapid, efficient rinsingand/or drying of wetted surfaces, and is particularly advantageous whenused to dry the lower surface of moveable barrier structures such as abarrier plate that overlies a workpiece being treated in such a mannerto define a tapering flow channel over the workpiece. In representativeembodiments, the lower surface of the barrier structure is provided withfeatures (including grooves or other depressions in the surface or rims,tabs or other protuberances from the surface) that help to collectand/or contain liquid on the lower surface. Aspirating and/or wickingtechniques are then used to remove the collected or contained liquid,e.g., to help dry the surface. The technique is fast and efficient,particularly when used in combination with drying gases or the like thatare caused to contact the same surface. The aspirated fluid can bewithdrawn in a variety of ways. For example, the aspiration inlet can belocated on the lower surface of the barrier structure, on an outer edge,or on a separate component placed in fluid communication with thebarrier structure.

The present invention also provides strategies to minimize thermaleffects between a spraying mechanism and a barrier plate. WhereasAssignee's Co-Pending Applications Nos. 1 and 2 describe an apparatus inwhich the spraying mechanism and the barrier plate are a single,integrated, relatively large thermal mass component, some aspects of theinvention involve providing these as separate components. The relativelylow thermal mass spraying mechanism will heat more quickly and moreuniformly. In other words, the degree to which the barrier platefunctions as a heat sink for the spray bar is minimized. Providing thespraying mechanism and barrier structure as separate components allowseach component to be independently fabricated from more purpose-suitablematerials. Recognizing that different materials may have different ratesof thermal expansion, preferred aspects of the invention couple thespraying mechanism to the barrier plate in a manner that helpsaccommodate differences in the rates of thermal expansion between thesecomponents.

The present invention also provides a simple, easily implemented way tohelp contain mists in a process chamber so that sprayed material has adramatically reduced tendency to escape from an opening in the processchamber. In representative embodiments, a venturi shaped pathway isplaced upstream or downstream from the open aperture. Material is easilycontained in the process chamber due to the pressure drop resulting whena gas stream is caused to flow through the venturi and into the processchamber. Since make up gas, inert gas, carrier gas, and/or the like, arewidely used in the course of treatments, this approach is compatiblewith many different kinds of treatments.

The present invention also provides a way to help ensure that thecentral region of a workpiece receives an appropriate treatment when aradius-type spray mechanism is used to spray treatment materials ontothe workpiece. It has been observed that the nozzle footprint throughwhich a spray is created may not match the on-workpiece footprint of thespray when the spray reaches the workpiece. The on-workpiece footprintis smaller than would be expected. Specifically, when liquid is atomizedwith a gas using a spraying mechanism such as spray bar 178, theon-workpiece footprint of the spray is smaller than the span of thenozzle array(s) from which the sprayed materials were dispensed. Thus,if the footprint of the nozzle openings merely span from the workpiececenter to the outer periphery, the resultant spray may not actuallyeffectively reach the center or the outer periphery, depending on spinspeeds, exhaust flow rates, spraybar height above the workpiece, and/orthe like. The high velocity of the dispensed gas develops a lowerpressure region believed to be due to a Bernoulli effect. The portionsof the spray array at the ends of the spray get drawn inward as shown inFIGS. 20 a through 20 c, described further below.

Consequently, at least some material aimed toward the workpiece centerdoes reach the center but rather impacts the workpiece more toward theperiphery. Because the workpiece typically is spinning during mosttreatments, and because the spinning causes material to flow generallyradially outward across the workpiece surface, the result is that theworkpiece center sees less treatment material than is desired.Processing there will tend to fall short of expectations as a result.

For instance, according to one example, less etching might occur in thecenter when an etching treatment is carried out. As another example,less particle removal efficiency may be observed in a particle removalprocess. The present invention significantly recognizes and accounts forthis effect when configuring a radius-type spray bar so that thedispensed spray, even if it shrinks due to a Bernoulli effect, willstill have a sufficient span to effectively treat the entirety of theworkpiece surface in a more uniform manner.

In one aspect, the present invention provides an apparatus forprocessing a microelectronic workpiece that includes a processingchamber in which the workpiece is positioned during a treatment, abarrier structure including a lower surface that overlies and at leastpartially covers the workpiece during the treatment, and an aspiratingpathway in fluid communication with the barrier structure in a mannereffective to allow liquid on the lower surface to be aspiratinglywithdrawn from the lower surface of the barrier plate.

In another aspect, the present invention provides an apparatus forprocessing a microelectronic workpiece that includes a processingchamber in which the workpiece is positioned during a treatment, abarrier structure including a lower surface having an outer periphery, afeature positioned in the apparatus in a manner effective to helpattract or help contain a liquid on the lower surface of the barrierstructure, and an aspirating pathway having a fluid inlet proximal tothe feature in a manner effective to allow the contained or attractedliquid to be withdrawn from the lower surface of the barrier plate. Thelower surface overlies and at least partially covers the workpieceduring the treatment.

In another aspect, the present invention provides a method of treating amicroelectronic workpiece that includes the steps of positioning theworkpiece in a processing chamber of an apparatus, causing a barrierstructure to overly the workpiece, subjecting the covered workpiece to atreatment that comprises introducing a liquid into the process chamber,and aspiratingly or wickingly removing a portion of the liquid thatcollects on the lower surface of the barrier structure. The barrierstructure includes a lower surface that overlies at least a portion ofthe workpiece during the treatment

In another aspect, the present invention provides a barrier structurethat includes an annular shaped body having a lower surface that isnonperpendicular to an axis of the body, and an aspirating and/orwicking pathway in fluid communication with the lower surface thatallows liquid on the lower surface to be withdrawn.

In another aspect, the present invention provides an apparatus forprocessing a microelectronic workpiece that includes a processingchamber in which the workpiece is positioned during a treatment, atleast one nozzle through which a spray of at least one treatmentmaterial is introduced into the processing chamber, and a venturi-shapedpathway through which at least one gas is introduced into the processchamber.

In another aspect, the present invention provides a method of treating amicroelectronic workpiece that includes positioning the workpiece in aprocessing chamber of an apparatus, causing a barrier structure tooverly the workpiece, spraying a treatment material onto the workpiece,causing a venturi shaped pathway to be fluidly coupled to the throughaperture, and during at least a portion of the spraying step, causing atleast one gas to flow through the venturi-shaped pathway in a mannereffective to help contain the mist in the process chamber. The barrierstructure includes an open, through aperture overlying a central portionof the workpiece. The spraying generates a mist.

In another aspect, the present invention provides a method of treating amicroelectronic workpiece that includes the steps of spraying at leastone liquid onto the workpiece while said workpiece is positioned in achamber having an aperture that is open during the spraying, providing aventuri-shaped pathway that is fluidly coupled to the open aperture, andusing a gas flow accelerated through the venturi-shaped pathway to helpcontain the sprayed liquid in the chamber.

In another aspect, the present invention provides a method of treating amicroelectronic workpiece that includes the steps of spraying at leastone liquid onto the workpiece while said workpiece is positioned in achamber having an aperture that is open during the spraying, providing aventuri-shaped pathway that is fluidly coupled to the open aperture, andusing a gas flow accelerated through the venturi-shaped pathway to helpcontain the sprayed liquid in the chamber.

In another aspect, the present invention provides an apparatus forprocessing a microelectronic workpiece that includes a processingchamber in which the workpiece is positioned during a treatment, saidworkpiece having a radius and a spraying mechanism that includes atleast a first array of nozzle openings through which a gas is dispensedand at least a second array of nozzle openings through which a liquid isdispensed. The first array of nozzle openings are positioned relative tosaid second array of nozzle openings in a manner effective to causedispensed gas and liquid to atomizingly collide in an open spaceexternal to the first and second arrays of nozzle openings to provide aspray that contacts the workpiece. At least one of the first and secondarrays of nozzle openings has a nozzle footprint that extends past thecenter of the workpiece in a manner effective to provide the spray withan on-workpiece footprint that spans a radius of the workpiece generallyfrom the workpiece center at least partially to the outer periphery ofthe workpiece. The on-workpiece footprint of the spray having a spanthat is less than the span of the nozzle footprint of said at least oneof the first and second arrays of nozzle openings.

In another aspect, the present invention provides a method of treating amicroelectronic workpiece that includes the steps of causing a gasstream to be dispensed from a first array of nozzle openings and causinga liquid stream to be dispensed from a second array of nozzle openings,causing the gas and liquid streams to atomizingly collide underconditions effective to generate a spray that contacts the workpiece.The workpiece has a center and a radius. The on-workpiece footprint ofthe spray generally corresponds to the radius of the workpiece. At leastone of the first and second arrays of nozzle openings has a dispensingfootprint that is larger than the on-workpiece footprint of the spray.The dispensing footprint extends past the center of the workpiece.

In another aspect, the present invention provides an apparatus forprocessing a microelectronic workpiece that includes a relatively lowthermal mass spraying mechanism that dispenses a spray onto theworkpiece and a relatively high thermal mass barrier plate overlying theworkpiece. The barrier plate includes at least one aperture throughwhich the spray is dispensed toward the workpiece.

In another aspect, the present invention provides a method of treating amicroelectronic workpiece that includes the step of using such anapparatus to dispense a material onto the workpiece.

In another aspect, the present invention provides an apparatus forprocessing a microelectronic workpiece that includes a sprayingmechanism having at least one array of nozzle openings through which afluid material is dispensed toward the workpiece, a barrier plate thathas at least one aperture through which the fluid material is dispensedtoward the workpiece, and a resilient element interposed between thespraying mechanism and the barrier plate in a manner effective to helpaccommodate a difference in the rates of thermal expansion between thespraying mechanism and the barrier plate. The spraying mechanism has afirst rate of thermal expansion and the barrier plate has a second rateof thermal expansion different from the first rate of thermal expansion.

In another aspect, the present invention provides a method of treating amicroelectronic workpiece that includes the step of using such anapparatus to dispense a material onto the workpiece.

In another aspect, the present invention provides an apparatus forprocessing a microelectronic workpiece that includes a processingchamber, a barrier structure, a spraying mechanism through which aliquid is dispensed, a feature to help attract or contain the liquid, anaspirating or wicking pathway, and a venturi-shaped pathway. Theworkpiece is positioned in the processing chamber during a treatment.The barrier structure includes a lower surface that overlies and atleast partially covers the workpiece during the treatment. The barrierstructure has a first aperture overlying a central portion of theworkpiece. The first aperture is open and through. The sprayingmechanism includes at least a first array of nozzle openings throughwhich a gas is dispensed and at least a second array of nozzle openingsthrough which a liquid is dispensed. The first array of nozzle openingsare positioned relative to the second array of nozzle openings in amanner effective to cause dispensed gas and liquid to atomizinglycollide in an open space external to the first and second arrays ofnozzle openings to provide a spray that contacts the workpiece. At leastone of the first and second arrays of nozzle openings has a nozzlefootprint that extends past the center of the workpiece in a mannereffective to provide the spray with an on-workpiece footprint that spansgenerally from the workpiece center at least partially to the outerperiphery of the workpiece. The on-workpiece footprint of the spray hasa span that is less than the span of the nozzle footprint of the atleast one of the first and second arrays of nozzle openings. The featureis positioned in the apparatus in a manner effective to help attract orhelp contain the liquid that is present on the lower surface of thebarrier structure. The aspirating or wicking pathway is in fluidcommunication with the barrier structure in a manner effective to allowthe liquid that is present on the lower surface to be withdrawn from thelower surface of the barrier structure. At least one gas is introducedinto the processing chamber through the venturi-shaped pathway. Theventuri-shaped pathway is fluidly coupled to the first aperture of thebarrier structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows an apparatus incorporating principles of thepresent invention.

FIG. 2 is a perspective view, with some features shown in cross-section,of the barrier/dispense section shown schematically in FIG. 1.

FIG. 3 is a perspective view, with some features shown in cross-section,of the barrier/dispense section shown schematically in FIG. 1.

FIG. 4 is a perspective view, with some features shown in cross-section,of the barrier/dispense section shown schematically in FIG. 1.

FIG. 5 is a perspective view of the barrier plate used in thebarrier/dispense section of FIG. 2, looking toward the top of thebarrier plate.

FIG. 6 is a perspective view of the barrier plate used in thebarrier/dispense section of FIG. 2, looking toward the bottom of thebarrier plate.

FIG. 7 is a perspective view of the barrier plate used in thebarrier/dispense section of FIG. 2, looking toward the top of thebarrier plate.

FIG. 8 is a perspective view of the barrier plate used in thebarrier/dispense section of FIG. 2, looking generally toward the bottomof the barrier plate.

FIG. 9 shows a portion of the barrier plate of FIG. 5 in which theaspiration trough can be seen along with some associated features andcomponents shown in cross-section.

FIG. 10 is a top view of the seal ring used to cover the aspirationtrough shown in

FIG. 9.

FIG. 11 is a side cross-section view of the seal ring shown in FIG. 10.

FIG. 12 is a schematic cross-section of the spray bar used in thebarrier-dispense section of FIG. 2, showing fluid pathways through whichmaterials may be dispensed through nozzle openings of the spray bar.

FIG. 13 is a perspective view of the spray bar used in thebarrier-dispense section of FIG. 2, generally looking toward the top ofthe spray bar.

FIG. 14 is a perspective view of the spray bar used in thebarrier-dispense section of FIG. 2, generally looking toward the bottomof the spray bar.

FIG. 15 is a perspective view showing an assembly including the spraybar of FIG. 14 placed into position in the pocket of the barrier plateof FIG. 5.

FIG. 16 is a perspective view of the retaining clamp used to hold thespray bar of FIG. 13 in the pocket of the barrier plate shown in FIG.15.

FIG. 17 is a top view of the retaining clamp used to hold the spray barof FIG. 13 in the pocket of the barrier plate shown in FIG. 15, withsome parts shown in phantom.

FIG. 18 is a perspective view of the filler piece used in the barrierdispense section of FIG. 2, looking toward the bottom of the fillerpiece.

FIG. 19 is a perspective view of the filler piece used in the barrierdispense section of FIG. 2, looking toward the top of the filler piece.

FIGS. 20 a, 20 b, and 20 c schematically illustrate how a Bernoullieffect can impact the on-workpiece footprint of an atomized spray.

FIG. 21 is a perspective view of an air intake flange used in thebarrier/dispense section of FIG. 2, generally looking at the top of theflange.

FIG. 22 is a perspective view of an air intake flange used in thebarrier/dispense section of FIG. 2, generally looking at the top of theflange and shown in cross-section.

FIG. 23 is a top view of the air intake flange used in thebarrier/dispense section of FIG. 2, generally looking at the top of theflange.

FIG. 24 is a perspective view of the showerhead spacer used in thebarrier/dispense section of FIG. 2 generally looking toward the top.

FIG. 25 is a perspective view of the showerhead spacer used in thebarrier/dispense section of FIG. 2 generally looking toward the bottom.

FIG. 26 is a top view of the showerhead spacer used in thebarrier/dispense section of FIG. 2.

FIG. 27 a side cross-section view of the showerhead spacer used in thebarrier/dispense section of FIG. 2.

FIG. 28 is a perspective view of the base used in the showerheadassembly of the barrier/dispense section of FIG. 2.

FIG. 29 is a top view of the base used in the showerhead assembly of thebarrier/dispense section of FIG. 2.

FIG. 30 is a side cross-section view of the base used in the showerheadassembly of the barrier/dispense section of FIG. 2.

FIG. 31 is a perspective view of the cover used in the showerheadassembly of the barrier/dispense section of FIG. 2.

FIG. 32 is a side cross-section view of the base used in the showerheadassembly of the barrier/dispense section of FIG. 2.

FIG. 33 is a bottom view of the cover used in the showerhead assembly ofthe barrier/dispense section of FIG. 2.

FIG. 34 is a perspective view with some features shown in phantom of thecenter dispense nozzle retainer used in the barrier/dispense section ofFIG. 2.

FIG. 35 is a top view of the center dispense nozzle retainer used in thebarrier/dispense section of FIG. 2.

FIG. 36 is a top view of the retainer used to help clamp the centerdispense nozzle retainer in FIGS. 34 and 35.

FIG. 37 is a perspective view of a rinse tube holder used in the barrierdispense section of FIG. 2.

DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS

The embodiments of the present invention described below are notintended to be exhaustive or to limit the invention to the precise formsdisclosed in the following detailed description. Rather the embodimentsare chosen and described so that others skilled in the art mayappreciate and understand the principles and practices of the presentinvention. While the present invention will be described in the specificcontext of fluid based microelectronic substrate cleaning systems, theprinciples of the invention are applicable to other microelectronicprocessing systems as well.

FIGS. 1 through 37 show an illustrative tool 10 that incorporatesprinciples of the present invention. For purposes of illustration, tool10 is of the type in which a single workpiece 18 is housed in the tool10 at any one time and subjected to one or more treatments in whichliquid(s), gas(es), and/or other processing media are caused to contactthe workpiece 18. In the microelectronics industry, for instance, tool10 may be referred to as a single wafer processing tool. Workpiece 18 istypically a semiconductor wafer or other microelectronic substrate.

Tool 10 generally includes as main assemblies a base section 12 and abarrier/dispense section 14. In FIG. 1, the base section 12 and thebarrier/dispense section 14 are shown schematically. In FIGS. 2 though37, details of the barrier/dispense section 14 and components thereofare shown in more detail. In actual use, the base section 12 and thebarrier/dispense section 14 would be mounted to a framework (not shown)and enclosed within a housing (not shown) of tool 10. This mounting canoccur in any manner such as via screws, bolts, rivets, adhesives, welds,clamps, brackets, combinations of these, or the like. Desirably, though,the sections 12 and 14 and/or components thereof are independently andremovably mounted to facilitate service, maintenance, upgrade, and/orreplacement.

Base section 12 and barrier/dispense section 14 help define processingchamber 16 in which workpiece 18 is positioned during processing. Basesection 12 and/or barrier/dispense section 14 include one or morefeatures or capabilities to allow workpiece 18 to be loaded into andtaken from processing chamber 16. Such features and capabilities mayinclude, for instance, a door that may be opened or closed to providethe desired egress. Alternatively, and as contemplated in preferredmodes of practice, base section 12 and barrier/dispense section 14 aremoveable relative to each other to provide this egress. Conveniently,this relative movement occurs by raising and lowering barrier dispensesection 14 while keeping base section 12 fixed to the surroundingframework (not shown).

As seen schematically in FIG. 1, base section 12 generally includes ahousing 17, chuck 20, motor 22, and backside dispense head 24. Insideprocessing chamber 16, workpiece 18 is supported and held by chuck 20.Chuck 20 is desirably cylindrical in shape and includes an upper face26, lower face 28, annular base 30, central through bore 32, andsidewall 34 at the outer periphery. Chuck 20 may be stationary or it maybe rotatable about a central axis 36. For purposes of illustration, thefigures illustrate an embodiment of tool 10 in which chuck 20 isrotatably driven by motor 22 so that workpiece 18 may be spun about axis36 during processing. In those embodiments in which workpiece 18 is spunby a rotating chuck 20, the spinning helps to spread dispensed treatmentmaterials uniformly over the workpiece 18. Motor 22 may be of the hollowshaft type and may be mounted to tool 10 by any convenient approach.

Chuck 20 may secure workpiece 18 in any of a variety of different waysin accordance with conventional practices now or hereafter developed.Preferably, chuck 20 includes edge gripping structures (not shown) thatsecurely hold workpiece 18 above upper face 25 of optional dispense head24 (discussed below) such that there is a gap between workpiece 18 andthe upper face 25. This kind of positioning allows treatment chemicals,including rinse water, to be dispensed onto either the upper face orlower face of workpiece 18.

Optionally, tool 10 may include dispense structure(s) for treating thelower face 19 of workpiece 18. An illustrative backside dispensemechanism is shown as a generally circular dispense head 24 in which oneor more treatment chemicals may be dispensed toward lower face ofworkpiece 18. Treatment chemicals are supplied to backside dispense head24 via shaft 38 that passes through central bore 40 of chuck 20 andcentral bore 42 of motor 22. In embodiments in which chuck 20 rotates,there are gaps between shaft 38, and central bores 40 and 42 so that theparts do not contact as the chuck 20 rotates. The backside dispense head24 may be coupled to one or more supplies (not shown) of treatmentmaterials to be dispensed as supplied or blended on demand.

In particularly preferred embodiments, the base section 12 is in theform of the “processing section 11” described and illustrated inassignee's Co-Pending Applications Nos. 1 and 2. In other words, thebarrier dispense section 14 of the present specification advantageouslymay be coupled to the “moveable member 526” and thereby substituted forthe “dispense assembly 554” of Assignee's Co-Pending Applications Nos. 1and 2.

FIGS. 2 through 37 show more details of an illustrative embodiment ofone kind of preferred barrier/dispense section 14 useful in dispensingone or more processing materials in the course of processing one or moremicroelectronic workpieces 18. The dispensing components ofbarrier/dispense structure 14 may be coupled to one or more supplies(not shown) of treatment materials provided via supply lines (notshown). These materials can be dispensed as supplied or blended ondemand. A wide variety of treatment materials may be used, as tool 10 isquite flexible in the types of treatments that may be carried out. Justa small sampling of representative treatment materials include gases andliquids such as nitrogen, carbon dioxide, clean dry air, argon, HF gas,aqueous HF, aqueous isopropyl alcohol or other alcohols and/ortensioactive material(s), deionized water, aqueous or other solutions ofammonium hydroxide, aqueous or other solutions of sulfuric acid, aqueousor other solutions of nitric acid, aqueous or other solutions ofphosphoric acid, aqueous or other solutions of hydrogen chloride,hydrogen peroxide, ozone gas, aqueous ozone, organic acids and solvents,combinations of these and the like.

Representative examples of processes and chemistries suitably practicedin tool 10 include those described in Publication No. 2006-0219258-A1,the disclosure of which is fully incorporated herein by reference. Otherrepresentative examples of processes and chemistries suitably practicedin tool 10 include those described in Assignee's co-pending applicationSer. No. 60/819,179, filed, Jul. 7, 2006, naming Jeffrey Butterbaugh asone of the inventors, and entitled LIQUID AEROSOL PARTICLE REMOVALMETHOD, the disclosure of which is fully incorporated herein byreference in its entirety for all purposes.

The preferred barrier/dispense section 14 comprises dispense assembly100 which desirably would be mounted to the lower end of “moveablesupport member 526” of Assignee's Co-Pending Applications Nos. 1 and 2.Dispense assembly 100 generally includes one or more independentmechanisms for dispensing treatment materials into the processingchamber 16. For instance, the illustrative embodiment of dispenseassembly 100 includes at least one, preferably at least two, and morepreferably at least three different kinds of dispensing capabilities. Asone capability, these mechanisms include one or more dispensingstructures that allow assembly 100 to spray one or more treatment fluidsdownward toward workpiece 18, generally across a radius of workpiece 18so that full surface coverage is obtained via rotation of the workpiece18 below the spray. In preferred embodiments, this capability isprovided by a dispensing structure such as spray bar 178. Centerdispense nozzle assembly 518 allows treatment materials to be dispenseddownward generally toward the center of workpiece 18. As workpiece 18spins, the centrally dispensed materials are distributed over theworkpiece surface. Additionally, showerhead dispense member 426 providesstill yet another way to introduce processing materials, typicallygases, vapors, and/or entrained materials into the processing chamber16.

In more detail, and as seen best in FIGS. 1 through 9 and 14, barrierplate 102 includes an annular body 104 having a lower surface 106, andupper surface 108, and inner periphery 110, and an outer periphery 112Inner periphery 110 is generally rounded to help promote smooth gas flowthrough the central apertures 120 and 122. Advantageously, lower surface106 of barrier plate 102 includes one or more features that help tocollect and remove liquid that may be present. These features mayinclude depressions (e.g., troughs, grooves, etc.) and/or protuberances(e.g., buttons, rims, posts, etc.), combinations of these, or the likethat help to attract, contain, and/or withdraw the liquid. Thesefeatures may be present on the barrier plate 102 itself or may beproximal to the barrier plate 102 in an operative manner.

The present invention contemplates that one or more strategies may beused singly or in combination for removing the liquid from the lowersurface 106 of the barrier plate 102. In some embodiments, sources ofone or more drying gases may be directed onto the lower surface 106 ofthe barrier plate 102 in order to blow the liquid away. In otherembodiments, wicking features may be included on or proximal to thelower surface 106 of the barrier plate 102. For example, if the lowersurface 106 of the barrier plate 102 is hydrophilic, hydrophilicfeature(s) may be positioned, or moved to a position, to wick awayliquid. Aspiration techniques may also be used, and this strategy isillustrated in the Figures.

For purposes of illustrating one way to apply aspiration techniques todry the barrier plate 102, FIGS. 6, 8, and 9 show annular rim 116 thatprojects downward from lower surface 106 proximal to the outer periphery112. As will be described further below, annular rim 116 helps tocollect liquids on the lower surface 106 so that these liquids can beaspirated away. Aspiration of the collected liquid helps to dry thelower surface 106 and to prevent unwanted dripping from lower surfaceonto the underlying workpiece 18. Via z-axis movement of “moveablesupport member 526” according to Assignee's Co-pending Applications Nos.1 and 2, the position of barrier plate 102 relative to the underlyingworkpiece 18 can be controlled.

Preferably, at least lower surface 106 of barrier plate 102 is angleddownward in a radially outward direction relative to the underlyingradii of workpiece 18 to establish a tapering flow channel 114 betweenworkpiece 18 and lower surface 106 of barrier plate 102. The taperingconfiguration of channel 114 helps to promote radial flow outward fromthe center of workpiece 18 while minimizing recirculation zones. Thetaper also helps to smoothly converge and increase the velocity offlowing fluids approaching the outer edge of workpiece 18. This helps toreduce liquid splash effects. The angle of lower surface 106 also helpsliquid on lower surface 106 to drain toward annular rim 116, where thecollected liquid can be aspirated away rather than drip downward ontoworkpiece 18 or the apparatus (not shown) used to deliver or removeworkpiece 18 from the process chamber 16. The tapering configurationalso helps to reduce recirculation of particles back onto workpiece 18.The configuration also helps facilitate chemical reclaim efficiency bybetter containment of fluids.

Additionally with respect to this particular embodiment, the generallyannular barrier plate 102 of dispense assembly 100 functions in onerespect as a lid over processing chamber 16 in order to help provide aprotected environment for workpiece treatment and to help containdispensed materials in the processing chamber 16. However, the generallyannular body 104 preferably does not seal processing chamber 16, butrather comes into close proximity with other barriers helping to defineprocessing chamber 16.

The angled lower surface 106 can have a variety of geometries. Forinstance, the geometry can be one or more of linear (conical),parabolic, polynomial, or the like. For purposes of illustration, thelower surface 106 generally linearly converges toward workpiece 18 in aradially outward direction.

Barrier plate 102 includes an arm 118 that subdivides the open centralarea into first and second intake apertures 120 and 122. Duringprocessing, fluid process media can be caused to flow into processingchamber 16 through these apertures. Viewable from top surface 108, arm118 and an adjoining portion of annular body 104 are shaped to provide apocket 124 for holding spray bar 178. Pocket includes side faces 126 andbottom 128. Bottom 128 includes a slot 130 through which spray bar 178sprays material downward onto workpiece 18 during processing. Centrallylocated holes 132 are formed in side faces 126. Central dispense nozzlefeatures (described further below) are fed through these holes 132 fordispensing treatment materials generally onto the center of theunderlying workpiece 18.

Viewable from top surface 108, arm 118 further includes a raised boss134 including threaded bore 136. Showerhead spacer 382 (discussedfurther below) is supported upon and secured to boss 134 using afastener such as a threaded screw. Additional raised bosses 140 aredistributed around inner periphery 110 of annular body 104. One or moreof these raised bosses 140 may include one or more threaded bores 142.Air intake flange 338 (described further below) is supported upon andfastened to these bosses 140 such as by screws threadably engagingthreaded bores 142. For purposes of illustration, four distinct raisedbosses 140 are shown. In other embodiments, more or less of these bosses140 may be used. In some embodiments, one or more of such bosses 140 mayspan longer portions of the inner periphery 110, although the use ofdiscrete bosses 140 as shown helps with weight reduction.

Additional raised bosses 146 are also provided on upper surface 108 oneach side of pocket 124 near outer periphery 112. Each of bosses 146includes at least one threaded bore 148. A retainer plate 266 (describedfurther below) is secured to these bosses 146 in order to help securespray bar 178 in pocket 124. The retainer plate 266 is fastened to thesebosses via screws that threadably engage the bores 148.

As part of the aspiration system incorporated into barrier plate 102, anannular trough 152 is formed in top surface 108 proximal to the outerperiphery 112 of annular body 104. Aspirating channels (not shown)extend between ports 156 located on the lower surface 106 of annularbody 104 to corresponding ports 158 opening into trough 152.

As seen best in FIGS. 2 through 4 and 9 through 11, seal ring 160 isfastened to annular body 104 over trough 152 to seal the top opening oftrough 152. Seal ring 160 may be secured to annular body 104 in anyconvenient fashion. By way of example, seal ring 160 includes an arrayof apertures 168 that allow seal ring to be secured over trough 152 byfastening screws 172 through apertures 168 and into threaded bores 170in the top surface 108 of annular body 104. The seal ring 160 isannularly shaped with a notch 166 through the ring defining ends 162 and164. The end 202 of spray bar 178 fits into this notch 166 when thespray bar 178 is fit into pocket 124 and secured in place. Additionally,seal ring 160 is provided with egress holes 174 and 176 that provideegress for plumbing components to access trough 152. For purposes ofillustration three pairs of holes 174 and 176 are provided in seal ring160. In representative embodiments, one hole 174 of each such pair iscoupled to plumbing (not shown) that allows a vacuum to be pulled ontrough 152. The vacuum helps to pull liquid material from the lowersurface 106 into trough 152 via aspiration channels (not shown). Theother hole 176 of each pair may be used to lead sump tubing deeper intotrough 152 to suck out liquid that is collected there. Advantageously,perimeter aspiration helps to keep the bottom of barrier plate 102 cleanand dry and also helps to prevent defects on workpiece 18 arising fromdrips or particles.

At least the lower surface 106 of annular body 104 may be hydrophilic orhydrophobic, as desired, depending upon the nature of the treatment(s)that might be carried out using tool 10. In preferred embodiments, it ispreferred that the lower surface 106 be made from a hydrophilic materialsuch as quartz, because this 1) facilitates drainage of liquids on thebarrier plate towards the aspirator on the edge, 2) causes liquids tospread out on the surface, leaving a thinner film and thus speedingdrying, and/or 3) maintains desirable hydrophilic properties whenexposed to many different chemicals.

Spray bar 178 is shown best in FIGS. 2 through 4 and 12 through 15.Spray bar 178 has top 188, bottom 180, first end 200 generally overlyingthe center area of the underlying workpiece 18, and second end 202generally overlying the outer periphery of the underlying workpiece 18.Spray bar 178 includes features facilitating assembly with othercomponents of dispense assembly 100. Additionally, pockets 208 and 212each include respective tabs 210 and 214. Respective o-rings (not shown)fit into these pockets and are sized so as to project above the surfaceof top 188. The o-rings provide a resilient bearing surface whensecuring the showerhead spacer 382 to the spray bar 178. The o-ringsfurther help to provide thermal isolation between the relatively lowthermal mass spraybar 178 and the relatively greater thermal massbarrier plate 102. This improves the temperature uniformity of fluidsdispensed through the spraybar which results in better processuniformity on the workpiece. Dispensing hot fluids through the spraybarcan result in significant temperature differentials between the spraybarand the barrier plate. The o-rings further help to provide a compliantmounting system that allows for differential thermal expansion betweenthe spraybar and barrier plate while minimizing stresses in componentsat higher dispense pressures.

Additionally, pocket 204 holds center dispense nozzle retainer 520 andincludes holes 206 allowing the center dispense tubes 522 to passthrough to a position at which the tubes 522 can deliver treatment mediato the process chamber 16.

Spray bar 178 further includes features that allow one or moreprocessing materials to be sprayed downward generally across a radius ofthe workpiece 18. A generally triangular groove 182 is formed on thebottom 180. Groove 182 includes an apex region 184 and adjoining faces186. Apex region 184 and faces 186 include nozzle features that allowmaterial(s) to be dispensed from spray bar 178 and sprayed onto theworkpiece 18. This groove 182 generally spans slightly more than thefull radius of the underlying workpiece 18 to help ensure that spraydispensed from the nozzle features has a spray footprint at theworkpiece that spans at least the full radius of the workpiece. Thefootprint of the sprayed material upon the workpiece 18 will bediscussed in more detail below in connection with FIGS. 20 a through 20c.

In order to supply treatment materials to the nozzle features of spraybar 178, supply tubes 222 and 246 convey such materials to fluid inletmember 216 and fluid inlet member 240. Fluid inlet member 216 is part ofa fluid pathway that conveys treatment materials to nozzle array 234 atthe apex 184 of groove 182. Channel 262 is part of a fluid pathwaybetween fluid inlet member 216 and nozzle array 234. Fluid inlet member216 includes threaded base 218 (threads not shown) and flare coupling220. Supply tube 222 is secured to flare coupling 220 by retaining nut224. Fluid inlet member 240 is part of a fluid pathway that conveystreatment materials to the nozzle arrays 260 provided on faces 186 ofgroove 182. Channels 264 and 265 are part of a fluid pathway betweenfluid inlet member 240 and nozzle arrays 260. Plugs 238 and 236 areinserted on the ends of channels 262, 264, and 265.

Fluid inlet member 240 includes threaded base 242 (threads not shown)and flare coupling 244. Supply tube 246 is attached to flare coupling244 and held in place by retaining nut 248. The fluid pathways betweenfluid inlet members 216 and 240 and their respective array(s) of nozzleopenings may be provided as shown with respect to the spray bar armsshown in Assignee's Co-Pending Patent Applications.

Liquids, gases, or combinations of these may be dispensed using spraybar 178. In typical embodiments, as shown in FIG. 12, liquid material(not shown) is conveyed through channels 264 and 265 and dispensedthrough nozzle arrays 260 on the faces 186 of the spray bar groove 182,while a pressurized gas (not shown) is conveyed through channel 262 anddispensed from the nozzle array 234 positioned along the apex 184 of thegroove 182. The gas jet collides with the liquid streams, atomizing theliquid material into fine droplets (not shown). After the collision, thegas jet helps transport the atomized liquid to the workpiece 18. Inother modes of practice, only liquid material is dispensed from thenozzle arrays on the adjacent faces. After colliding, the combinedliquid stream contacts the workpiece 18. In other aspects of practice,only gas material(s) may be dispensed through nozzle array at the apexand/or the nozzle arrays at the adjacent faces.

The nozzle spacing, dispense trajectory with respect to the surface ofworkpiece 18, the orifice size of the nozzle openings, and the like maybe varied to adjust the characteristics (e.g., spray characteristics) ofthe dispensed streams. For instance, the nozzle spacing and openingsizes may be uniform or varied.

However, it has now been observed that the footprint of a spray upon theunderlying workpiece is smaller than might be expected. Specifically,when liquid is atomized with a gas using a spraying mechanism such asspray bar 178, the on-workpiece footprint of the spray is smaller thanthe span of the nozzle array(s) from which the sprayed materials weredispensed. Thus, if the footprint of the nozzle openings merely spanfrom the workpiece center to the outer periphery, the resultant spraymay not actually effectively reach the center or the outer periphery,depending on spin speeds, exhaust flow rates, spraybar height above theworkpiece and combinations thereof. The high velocity of the dispensedgas develops a lower pressure region due to the Bernoulli effect whichcauses the spray to angle inward as the spray moves toward theworkpiece. The portions of the spray array at the ends of the spray getdrawn inward as shown in FIGS. 20 b and 20 c. FIGS. 20 a-20 c illustratethe trajectory of spray 310, 320, and 330, respectively, with respect toworkpieces 312, 322, and 332, respectively. Like workpiece 18,workpieces 312, 322, and 332, are typically a semiconductor wafer orother microelectronic substrate.

FIG. 20 a shows an idealized situation in which a spray bar 308dispenses a spray 310 onto underlying, spinning workpiece 312. Thelength of the footprint of the spray as it is dispensed matches theon-workpiece footprint of the spray. With the spray footprint asdispensed matching the workpiece 312 radius between center 316 and outerperiphery 314, full radius coverage of the workpiece 312 is achieved. Asthe workpiece 312 spins about its center 316, the full surface of theworkpiece 312 is uniformly treated. This idealized situation isgenerally representative of a mode of practice in which liquid materialis dispensed onto workpiece 312 without atomization via impingement witha separate gas stream.

FIG. 20 b schematically shows that the situation is different when a gasstream is used to atomize the liquid stream(s), particularly when theatomization is achieved via a collision between at least one gas streamand at least one liquid stream. In FIG. 20 b, spray bar 318 dispensesatomized spray 320 onto underlying spinning workpiece 322. As dispensed,the spray footprint matches the radius of the workpiece 322 between theworkpiece center 326 and the workpiece outer periphery 324. However, thefootprint of the spray 320 is reduced by the time the spray 320 reachesworkpiece 322. Due to the atomizing of the liquid stream(s) with atleast one gas stream a Bernoulli effect is established that draws theouter atomized flow streams inward as shown in FIG. 20 b. In an etchingor particle removal process, for instance, the on-workpiece consequenceof this effect is that the workpiece center or periphery may experienceless etching or particle removal, as the case may be. The effect appearsto be of a greater magnitude at the workpiece center than at theworkpiece perimeter, but the effect is observable in both regions. Withrespect to the workpiece center 326, the spray 320 is not fullydispensed onto the workpiece center 326 due to the Bernoulli effect andthe workpiece center 326 remains starved of spray 320 material becauseafter the spray 320 material contacts spinning workpiece 322 the spray320 material tends to flow radially outward away from the workpiececenter 326 during the course of treatment. With respect to the workpieceouter periphery 324, the spray 320 is not fully dispensed onto theworkpiece periphery 324 due to the Bernoulli effect yet the spinning ofworkpiece 322 causes mass flow of the dispensed spray 320 material toflow radially outward and treat the outer periphery 324 such that outerperiphery 324 is not as starved overall as the workpiece center 326.

The present invention advantageously helps to overcome the Bernoullieffect by first recognizing the effect and then using a spray bar thatdispenses a spray with a large enough footprint so that the reduced,on-workpiece footprint is still large enough to generally effectivelytreat the workpiece center region in a reasonably uniform manner withrespect to other surface regions of the workpiece. The effect is easierto accommodate at the outer periphery for at least two reasons. First,the Bernoulli effect appears to have less of an impact upon processuniformity at the outer periphery. It is believed that the effect islesser at the outer periphery at least partly because the general massflow of dispensed liquid is radially outward across the spinningworkpiece. Thus, the outer periphery is not as starved for treatmentmaterial as is the central region over the course of a treatment.Second, the spray footprint can extend well beyond the workpieceperimeter, subject to practical constraints of not wasting too muchtreatment material.

Generally, the amount of footprint “lost” as the spray travels towardthe workpiece may be determined empirically. Then, enough extra nozzlescan be added to the array so that the spray is still large enough tospan the workpiece radius when the spray reaches the workpiece. Forinstance, if the spray loses about 10.5 mm on each end, adding 3 extranozzle elements, or portions of nozzle elements, at one or both ends ofthe spray bar, preferably at least at the end overlying the workpiececenter, on 3.5 mm centers would overcome the loss. According to oneempirical methodology for evaluating the loss of spray footprint, aspray bar with a particular spray footprint can be used to subject aworkpiece to a test treatment such as an etching treatment, a particleremoval treatment, or the like. It is often convenient to begin thisempirical analysis with a spray bar having a nozzle footprint that ispositioned so that the nozzle footprint closely matches the workpiececenter. That is, it is desirable that the most radially inboard nozzleopening directly overlies the workpiece center. It is also convenientthat the nozzle footprint at least reach, or extend past the outerperiphery of the workpiece. After the treatment, the treated workpiececan be analyzed to assess process performance as a function of distancefrom the center of the workpiece. If the Bernoulli effect is present, adistinct impairment of process performance will be observed in theworkpiece region proximal to the workpiece center.

A number of strategies may be used to modify a spray bar whenimplementing this approach. According to one strategy, an array(s) ofnozzles can be shifted along the radius of the workpiece 18 to helpensure that the footprint of the spray on the workpiece 18 includes atleast the center of the workpiece 18.

In another strategy, extra nozzle(s) can be added to a nozzle array toextend its footprint. As schematically shown in FIG. 20 c, extranozzle(s) are added to spray bar 328 such that the extra nozzle(s) arepositioned past the workpiece center 336 of workpiece 332 to helpcompensate for the Bernoulli effect. That is, as spray bar 328 dispensesspray 330 onto underlying workpiece 332, the on-workpiece sprayfootprint more closely matches the workpiece radius between theworkpiece center 336 and the workpiece outer periphery 334. An exampleof including extra nozzle(s) involves including one or more extra sprayelements to extend the spray bar footprint. When using the spray bar178, this would involve adding three extra nozzle holes per element. Onehole would be the gas dispense nozzle at the apex 184 of the groove 182,while two additional liquid dispense nozzle openings are added next tothe additional gas opening on the adjacent faces 186. Another example ofincluding extra nozzle(s) involves adding only one or more additionalgas dispense nozzles to the nozzle array to extend its footprint.Another example of including extra nozzle(s) involves adding only one ormore additional sets of liquid dispense nozzle openings to extend thenozzle footprint. The additional nozzle openings may be the same size ordifferently sized from the other nozzle openings of the spray bar.

Referring again to FIGS. 2-4 and 12-15, in one embodiment a nozzle array234 at the apex 184 includes a row of nozzle openings that are 0.020inches in diameter and that are spaced at 3.5 mm centers. The array ofnozzles on the apex 184 of groove 182 desirably is slightly longer thanthe radius of the workpiece to help ensure that the footprint of thespray on the workpiece 18 matches the radius of workpiece 18,particularly at least at the center. For example, the total span ofarray 234 includes additional nozzle holes that extend past the centerof the workpiece 18 on the inboard end 200 and optionally may includenozzle holes that extend beyond the periphery of the underlyingworkpiece 18.

In similar fashion, in one embodiment each of nozzle arrays on theadjacent faces 186 includes nozzle openings that correspond to the arrayof nozzles on the apex 184 to enable atomization and are 0.026 inches indiameter and that are spaced at 3.5 mm centers. The arrays 260 ofnozzles are slightly longer than the radius of the workpiece to helpensure that the footprint of the spray on the workpiece 18 matches theradius of workpiece 18, particularly at least at the center of theworkpiece. For example, the total span of each array 260 includesadditional nozzle holes that extend past the center of the workpiece 18on the inboard end 200 and optionally may include additional nozzleholes that extend beyond the periphery of the underlying workpiece 18.

In preferred embodiments, spray bar 178 fits into, but is a separatecomponent from, barrier plate 102. This approach provides numerousadvantages. Firstly, it allows each of these components to be made fromdifferent materials more suitable for the intended purposes of eachcomponent. For instance, in the case of spray bar 178, as well as otherdispensing components of tool 10, dispensing components of tool 10 inthe fluid delivery/wetted path, or at least surfaces thereof, preferablyare formed from one or more fluoropolymers for high purity. Thesecomponents include spray bar 178, the showerhead assembly 426, and atleast the tubing of the center dispense nozzle assembly 518.Polytetrafluoroethylene (available under the tradename TEFLON from E.I.Du Pont de Nemours & Co.) has been found to be suitable. On the otherhand, the barrier plate 102, or at least its lower surface 106,desirably is made from a hydrophilic material such as quartz or the likein order to optimize the cleaning and drying of the lower surface 106.Specifically, a hydrophilic surface such as quartz will tend to be moreefficient to rinse and dry as compared to a hydrophobic surface in manyinstances.

Using separate spray bar and barrier plate components also allows betterthermal isolation between the spray bar 178 and the barrier plate 102.When the spray bar and barrier plate are a single, integrated component,the whole unit has a relatively large thermal mass that can act as aheat sink when heated fluids are dispensed on the workpiece 18. Theeffect is a temperature drop between the fluid entering the spraybar andthe relatively cooler fluid leaving at the outboard end of the spraybardue to heat loss to the thermal mass of the barrier plate. Thistemperature difference along the spraybar results in temperaturenon-uniformity of the materials dispensed on the workpiece. This cannegatively affect the process uniformity on the workpiece and fromworkpiece to workpiece. However, when the spray bar 178 is a separatecomponent as shown, the thermal mass is greatly reduced. Also, byfitting the spray bar 178 into pocket 124 of barrier plate 102 with onlynozzle area of groove 182 exposed through slot 130, the area of thespray bar 178 exposed to the process chamber 16 is minimized and thespray bar 178 is thermally shielded by barrier plate 102 to a largeextent. This approach thermally isolates spray bar 178 from workpiece 18to a great extent, minimizing non-uniform thermal effects that couldcompromise process performance.

The use of the resilient bearing surfaces also accommodates thedifference in thermal expansion between the spray bar 178 and thebarrier plate 102 in those embodiments in which the two components areformed from different materials or operate at significantly differenttemperatures. The use of the resilient o-rings as bearing surfaces alsominimizes surface contact between the spray bar 178 and the barrierplate 102. This helps to thermally isolate the spray bar 178, helping tocounter thermal effects from heated fluid/chemical delivery fromtransferring heat to the barrier plate 102 and then, ultimately, to theworkpiece 18.

The retainer plate 266 helps to secure spray bar 178 into pocket 124 ofbarrier plate 102. FIGS. 2, 16 and 17 show the retainer plate 266 inmore detail. Retainer plate 266 includes top 268, bottom 270, and sides272, 274, 276 and 278. Retainer plate 266 includes apertures 282 so thatscrews or other suitable fastening technique (not shown) can engagethreaded bores 148 to secure retainer plate to barrier plate 102. Thebottom 270 includes a pocket 284 having a tab 286. An o-ring (not shown)fits into the pocket 284. The o-ring is sized so that it is compressedto provide a resilient bearing surface between retainer plate 266 andspray bar 178 when retainer plate 266 clamps the spray bar 178 intoposition.

Referring to FIGS. 2, 18, and 19, filler piece 288 is fitted in notch166 between ends 162 and 164 of seal ring 160. Filler piece 288 includestop 290, bottom 292, and sides 294, 295, 296, and 297. Trough 301 isformed in bottom to form a pathway to interconnect trough 152 betweenends 162 and 164. Filler piece 288 also includes tail 303 to fill a gapbetween spray bar 178 and barrier plate 102, preventing leakage therethat might otherwise occur. Notch 305 provides stress relief, allowingfiller piece 288 to conform and fit intimately with recess 299 ofbarrier plate 102. Filler piece 288 is held in place by spraybar 178 andseal ring 160.

Plumbing, air intake and the like may be fed through a central chimneypathway 103 (shown schematically in FIG. 1) of the barrier/dispensesection 14. The chimney may be open in many modes of practice, evenduring processing. One issue, then, is to contain dispensed materials inprocess chamber 16, especially sprayed materials and gases, when thechimney path is in an open condition. One option is to make chimneypathway 103 sufficiently tall to achieve the desired degree ofcontainment. However, this approach would require a relatively lengthychimney. When tool 10 is integrated in a stacked fashion in a largertool cluster (not shown), using vertical space more efficiently is anincreasingly higher priority.

Accordingly, the present invention may implement one or more strategiesthat allow shorter length chimneys to be used while still achieving thedesired degree of containment. According to one approach, a suitable gasflow (e.g., intake air or the like) is introduced into process chamber16 through the chimney pathway 103 during at least a portion ofprocessing. By using such a gas flow, better stacking efficiency amongtool stations can be achieved because the chimney can be shorter.

A particularly preferred mode of practice involves providing the chimneypathway with a venturi-shaped contour. A venturi generally includesflaring ends at the inlet and outlet and a relatively narrow throatinterposed between the inlet and outlet. The contour of the venturidesirably is generally smooth to promote smooth air flow and minimizeturbulence. The venturi helps to accelerate the gas flow through thethroat with a minimal pressure drop. The venturi provides excellentcontainment while allowing further reduction in chimney height ascompared to an ordinary cylindrical pathway.

In an illustrative mode of incorporating a venturi into the chimneypathway 103, the chimney pathway 103 is provided with venturi featuresvia the use of air intake flange 338. Air intake flange 338 is shownbest in FIGS. 2-4 and 21-23. Air intake flange 338 includes body 340 topend 342, rounded rim 344 at top end 342, and bottom end 348. Theunderside of rounded rim 344 includes and annular trough 346 providedfor weight savings. Each of inner wall 350 and outer wall 360 extendsfrom top end 342 and bottom end 348. Outer wall 360 is faceted, ratherthan being parallel to inner wall 350 to provide access to mountinghardware and for weight savings.

Advantageously, the inner wall 350 is shaped to provide venturi-shapedpassages 352 on each side of spray bar 178. Each of passages 352includes a relatively narrow throat 354 in which the passage 352 isconstricted and relatively broader, flaring ends 356 and 358. In use,flaring end 356 functions as an inlet through which one or more gasessuch as air, clean dry air, nitrogen, carbon dioxide, argon, isopropylalcohol vapor, combinations of these and the like are drawn into airintake flange 338. Flaring end 358 functions as an outlet through whichone or more gases is discharged downward into processing chamber 16. Asgas flows through the venturi-shaped passages 352, the velocityincreases as the passages constrict. As the flow rate increases, thepressure of the flowing gas decreases. This means that the pressure inthe venturi is relatively higher near flaring inlet end 356 andrelatively lower at the throat 354. The pressure through the venturidecreases with increasing velocity. Thus, when the flow rate through theventuri is high enough, the relatively higher pressure at the inlet end356 is high enough to help contain processing materials in theprocessing chamber 16. In short, the venturi-shaped passages 352function as a containment system in situations in which treatmentmaterials, which may be liquid, solid, or gas, must be contained in achamber that requires an opening for the introduction of processinggases.

For example, during a typical process, make-up air or other gas entersthe process chamber through the venturi-shaped passages 352. Theincoming air or gas accelerates as it passes through the throats of thepassages 352. The high velocity air or gas moving through the throat 354and into the chamber 16 prevents mist from escaping back up air intakeflange 338. In contrast, in an air intake passage lacking a throatconstriction or sufficient height, process chamber mist can escape,causing safety concerns, leading to contamination, reduced processperformance due to loss of processing material and the like.

In one illustrative operation condition, substantially complete mist andsteam containment was achieved using 50 cfm inlet air. This was achievedusing 3 inches of exhaust vacuum. In this test, the workpiece was spunon its chuck at 250 rpm while being sprayed with 1 liter per minutedeionized water at 65° C. The width of each of the venturi throats was1.12 inches, while each corresponding inlet and outlet had a width of1.75 inches. The length of each of the venturi-shaped passages was threeinches.

Still referring mainly to FIGS. 2-4 and 21-23 in discussing air intakeflange 338, the bottom portion of outer wall 360 is shaped so that airoutlet flange 368 fits onto inner periphery 110 of barrier plate 102.The bottom portion 370 of inner wall 350 is shaped to provide a smoothtransition from inner wall portion 370 to the lower surface 106 ofbarrier plate 102.

Peripheral flange 372 surrounds body 340 of air intake flange 338proximal to bottom end 348. Peripheral flange 372 reinforces body 340.Peripheral flange 372 also includes apertures 374 so that air intakeflange 338 can be secured to threaded bores 142 of barrier plate 102using screws or the like. Standoff supports 380 threadably engagethreaded bores 378 formed in rounded rim 344. Standoff supports 380,which include threaded bores (not shown), help to support and secureshowerhead assembly 426, described further below.

Inner wall 350 of air intake flange 338 also includes opposed pockets362 and 366. These pockets are sized to hold showerhead spacer 382,described further below. The wall of pocket 362 includes a trio of holes364. One, two, or all of these holes 364 may be used to lead plumbingcomponents, e.g., tubing, through flange 338.

In addition to spraying capabilities, dispense assembly 100 furtherincorporates further dispensing capabilities to dispense one or moretreatment fluids showerhead-style generally downward toward workpiece18. This approach is especially useful for dispensing uniform flows ofone or more gases and/or vapors into processing chamber 16. In preferredembodiments, this capability is provided by a dispensing structure suchas showerhead dispense member 426. Showerhead spacer 382 and standoffsupports 380 help to mount and support showerhead dispense member 426.For purposes of illustration, showerhead dispense member 426 is fed bytwo supply feeds, which may be the same or independent, thus allowingtwo different treatment materials to be dispensed into processingchamber 16 at the same time. Of course, other embodiments may includeonly a single supply feed or three or more feeds, as desired.

In more detail, and as seen best in FIGS. 2-4 and 24-27, showerheadspacer 382 includes top 384, bottom 386, floor 408, and sides 390, 396,400, and 404. Side 390 includes a trio of holes 392 that respectivelymatch up with holes 364 through air intake flange 338. In use, the setsof holes 364 and 392 may be used to lead plumbing components (not shown)through showerhead spacer 382 and air intake flange 338. One or more ofthese sets of holes 364 and 392 may be used for this purpose. Forexample, in one illustrative embodiment, a tubing (not shown) coupled toan exhaust source (not shown) is fed downward through the interior ofshowerhead spacer 382 and then fed outward through spacer 382 and airintake flange 338 through one set of holes 392 and 364, respectively.Outside the air intake flange 338, the tubing is joined to three othertubes that are respectively led to the egress holes 174 provided in sealring 160. The tubing is inserted far enough into holes 174 to pull anaspirating vacuum in trough 152. Additional tubing (not shown) issimilarly fed downward through the interior of showerhead spacer 382 andthen fed outward through spacer 382 and air intake flange 338 throughanother set of holes 392 and 364, respectively. Outside the air intakeflange 338, the additional tubing is joined to three other tubes thatare respectively led to the egress holes 176 provided in seal ring 160.The tubing is inserted far enough into holes 176 to remove liquidmaterial collected in trough 152.

Weight saving holes 394 are formed in the top of sides 390 and 396.Sides 400 and 404 each include respective trios of holes 402. Holes 402are used to hold rinse tube holders 510. As shown in FIG. 37, each rinsetube holder 510 includes a neck 512, body 514, and aperture 516. Necks512 engage holes 402, preferably with a threadable engagement (threadfeatures not shown). Rinse tubes 504 are led through apertures 516downward into process chamber 16. The ends of these tubes are positionedat a height so that nozzles 508 at the ends of the tubes can spraygenerally horizontally to rinse or otherwise treat the lower surface 106of barrier plate 102.

Advantageously, the rinse tubes 504 incorporate the ability to rinse anddry the bottom surface 106 of barrier plate 102 to help keep the barrierplate 102 clean and dry. In a typical mode of practice, the cleaning anddrying of barrier plate 102 occurs with the workpiece 18 present and atleast partially co-extensive with the rinsing and drying of workpiece 18in order to minimize cycle time. It can be difficult to remove liquiddroplets near the outer periphery 112 of the lower surface 106. Theaspirator system incorporated into the barrier plate 102 helps avoidthis difficulty.

Floor 408 includes hole 410 so that screw 138 can engage threaded bore136 in raised boss 134 to secure showerhead spacer 382 to barrier plate102. Floor 408 includes hole 412 for securing center dispensecomponentry described further below. Holes 414 allow supply tubing to beled to the center dispense componentry. Holes 416 and 418 fit over fluidinlet members 216 and 240, respectively. O-rings (not shown) fit intocavities 419 between showerhead spacer 382 and spray bar 178 and betweenshowerhead spacer 382 and barrier plate 102.

Showerhead spacer 382 is installed so that bottom ends 420 and floor 408are supported upon the top surfaces of spray bar 178, while legs 422 fitaround arm 118 of barrier plate 102. The outer surfaces 424 of legs 422are shaped to match the side faces 126 of pocket 124.

Showerhead dispense member 426 is mounted between the standoffs 380 andthe “moveable support member” as described in Assignee's Co-PendingApplications Nos. 1 and 2. Showerhead dispense member 426 generallyincludes bottom 428 and cover 458. Bottom 428 includes generallycircular floor panel 430 having a generally rectilinear central aperture432 and flange 434 projecting downward from the rim of central aperture432. The flange 434 and aperture 432 are sized to fit over underlyingand support showerhead spacer 382. The central aperture 432 provides aconvenient pathway for leading plumbing components to the centraldispense nozzle assembly 518 and spray bar 178.

Floor panel 430 includes several aperture features that facilitate thefunctionality and mounting of showerhead dispense member 426. On eachside of central aperture 432, floor panel 430 includes apertures 444which help support and lead rinse tubes 504 to process chamber 16.Relatively large through apertures 446 around the periphery of bottom428 are used to mount bottom 428 to standoff supports 380 using screwsor the like. Relatively smaller, threaded bores 448 allow the cover 458and moveable member (not shown, but described in Assignee's Co-PendingApplication) to be mounted to bottom 428 using screws or the like.

Floor panel 430 of bottom 428 includes first region 450 to one side ofcentral aperture 432 and second region 454 positioned on the other sideof central aperture 432. First region 450 includes an array of nozzleopenings 452, while second region 454 includes a second array of nozzleopenings 456.

Cover 458 generally includes raised panels 460 and 464. First and secondchambers 462 and 466 are formed between panels 460 and 464, on the onehand, and floor panel 430 on the other. Central aperture 492 overliescentral aperture 432 of bottom 428, providing a convenient pathway forleading plumbing components to center dispense nozzle assembly 518 andspray bar 178. On top of cover 458, notches 494 and 496 are used fordrainage in case of a leak.

One or more treatment materials, typically gases and/or vapors, may besupplied to showerhead dispense member 426 and are introduced intoshowerhead dispense member 426 via fluid inlet members 468 and/or 480.Fluid inlet member 468 includes threaded base 470 and flare coupling472. A supply tube (not shown) is fluidly coupled to flare coupling 472and held in place via a retainer nut (not shown) that threadably engagesthreaded base 470. Conduit 478 opens into chamber 462. Fluid inletmember 480 includes threaded base 482 and flare coupling 484. A supplytube (not shown) is fluidly coupled to flare coupling 484 and held inplace via a retainer nut (not shown) that threadably engages threadedbase 482. Conduit 490 opens into chamber 466.

On each side of central aperture 492, apertures 498, which directlyoverlie apertures 444, help support and lead rinse tubes 504 to processchamber 16. Relatively large through apertures 500 around the peripheryof cover 458 overlie similar apertures 446 on bottom 428 and similarlyare used to mount cover 458 to standoff supports 380 using screws or thelike. Relatively smaller, through bores 502 overlie threaded bores 448and allow the cover 458 and moveable member to be mounted to bottom 428using screws or the like.

In use, one or more treatment fluids, especially one or more flows ofgas(es), are supplied to showerhead dispense member 426 via one or twosupply tubes (not shown). The treatment fluids supplied to each tube maybe the same or different. The treatment fluids are introduced intochambers 462 and 466 via conduits 478 and 490, respectively. Thepressure of the treatment fluid(s) within chambers 462 and 466 isgenerally equalized so that the flow through the nozzles 452 and 456 isuniform. Desirably, the pressure differential of the fluid(s) withinchambers 462 and 466 upstream from the showerhead nozzles is desirablyless than pressure drop through the nozzles 452 and 456 themselves inaccordance with conventional practices to promote such uniform flow.When dispensed through the nozzles 452 and 456, the dispensed fluid(s)generally flow towards process chamber 16 and workpiece 18 through theventuri shaped pathways 352. Dispense assembly 100 further incorporatesdispensing capabilities to dispense one or more treatment fluidsgenerally onto the center of the underlying workpiece 18. The treatmentfluids may be dispensed serially, simultaneously, in overlappingfashion, and/or the like. In preferred embodiments, this capability isprovided by a dispensing structure such as central dispense nozzleassembly 518. For purposes of illustration, central dispense nozzleassembly 518 as shown includes two independent nozzles allowing twodifferent treatment materials to be dispensed onto workpiece 18 at thesame time. Of course, other embodiments may include only a singledispensing nozzle or three or more nozzles, as desired. Also, the sametreatment material could be dispensed through both nozzles.

In more detail, as shown in FIGS. 2-4, 34, and 35, central dispensenozzle assembly 518 generally includes nozzle retainer 520 fitted withnozzle tubes 522 in apertures 524. Tubes 522 include flare couplings 526seated against the top of nozzle retainer 520. Supply tubes 528 arecoupled to the flare couplings 526 and held in place by retaining nuts530. The bottom ends of the tubes 522 project downward below nozzleretainer 520 and are generally aimed at the center of the underlyingworkpiece 18. Nozzle retainer 520 fits into pocket 204 of spray bar 178.Screw 540 fits into threaded bore 532 of nozzle retainer 520.

As shown in FIGS. 2-4, retainer 534 and screw 540 are used to help clampnozzle retainer 520 securely in place. As shown in FIGS. 2-4 and 36, theretainer 534 includes apertures 536 that fit over and support the supplytubes 528. Aperture 538 of retainer 534 fits the screw 540.

Other embodiments of this invention will be apparent to those skilled inthe art upon consideration of this specification or from practice of theinvention disclosed herein. Various omissions, modifications, andchanges to the principles and embodiments described herein may be madeby one skilled in the art without departing from the true scope andspirit of the invention which is indicated by the following claims.

1.-9. (canceled)
 10. A method of treating a microelectronic workpiece,comprising the steps of: a) causing a gas stream to be dispensed from afirst array of nozzle openings; b) causing a liquid stream to bedispensed from a second array of nozzle openings; and c) causing the gasand liquid streams to atomizingly collide under conditions effective togenerate a spray that contacts the workpiece and forms an on-workpiecefootprint, said workpiece having a center and a radius; wherein theon-workpiece footprint spans from the workpiece center at leastpartially to the outer periphery of the workpiece and wherein at leastone of the first and second arrays of nozzle openings has a dispensingfootprint that is larger than the on-workpiece footprint of the spray,said dispensing footprint extending past the center of the workpiece.11. The method of claim 10, wherein the method of treating comprises anetching treatment.
 12. The method of claim 10, wherein the method oftreating comprises a particle removal treatment.
 13. The method of claim10, wherein the on-workpiece footprint of the spray corresponds to theradius of the workpiece.
 14. The method of claim 10, wherein the firstand second arrays of nozzle openings have a nozzle footprint thatextends past the center of the workpiece in a manner effective toprovide the spray with an on-workpiece footprint that spans from theworkpiece center at least partially to the outer periphery of theworkpiece.
 15. The method of claim 10, wherein the first and secondarrays of nozzle openings have a nozzle footprint that extends from theouter periphery of the workpiece to past the center of the workpiece.16. The method of claim 10, further comprising a third array of nozzleopenings through which a liquid is dispensed, wherein said first,second, and third arrays of nozzle openings are positioned relative toeach other in a manner effective to cause dispensed gas and liquid toatomizingly collide in an open space external to the first, second, andthird arrays of nozzle openings to provide a spray that contacts theworkpiece.
 17. The method of claim 16, wherein the first, second, andthird arrays of nozzle openings have a nozzle footprint that extendspast the center of the workpiece in a manner effective to provide thespray with an on-workpiece footprint that spans from the workpiececenter at least partially to the outer periphery of the workpiece. 18.The method of claim 16, wherein the first, second, and third arrays ofnozzle openings have a nozzle footprint that extends from the outerperiphery of the workpiece to past the center of the workpiece.
 19. Themethod of claim 16, wherein the first, second, and third arrays ofnozzle openings have a nozzle footprint that extends from beyond theouter periphery of the workpiece to past the center of the workpiece.20. The method of claim 10, wherein the first and second arrays ofnozzle openings have a nozzle footprint that extends from beyond theouter periphery of the workpiece to past the center of the workpiece.